^^&&^^

Edit File: innodb-truncate.test

--source include/have_innodb.inc

--echo #
--echo # TRUNCATE TABLE
--echo #
--echo # Truncating is disallowed for parent tables unless such table
--echo # participates in self-referencing foreign keys only.
--echo #
CREATE TABLE t1 (pk INT PRIMARY KEY) ENGINE=INNODB;
CREATE TABLE t2 (fk INT NOT NULL, FOREIGN KEY (fk) REFERENCES t1 (pk)) ENGINE=INNODB;
--error ER_TRUNCATE_ILLEGAL_FK
TRUNCATE TABLE t1;
--echo # Truncation of child should succeed.
TRUNCATE TABLE t2;
DROP TABLE t2;
DROP TABLE t1;
CREATE TABLE t1 (pk INT PRIMARY KEY, fk INT,
                 FOREIGN KEY (fk) REFERENCES t1 (pk)) ENGINE=INNODB;
--echo # Truncation of self-referencing table should succeed.
TRUNCATE TABLE t1;
DROP TABLE t1;

--echo #
--echo # Also, truncating such tables is allowed if foreign key
--echo # checks are disabled.
--echo #

SET @old_foreign_key_checks = @@SESSION.foreign_key_checks;
CREATE TABLE t1 (pk INT PRIMARY KEY) ENGINE=INNODB;
CREATE TABLE t2 (fk INT NOT NULL, FOREIGN KEY (fk) REFERENCES t1 (pk)) ENGINE=INNODB;
CREATE TABLE t3 (pk INT PRIMARY KEY, fk INT,
                 FOREIGN KEY (fk) REFERENCES t1 (pk)) ENGINE=INNODB;
SET @@SESSION.foreign_key_checks = 0;
TRUNCATE TABLE t1;
TRUNCATE TABLE t2;
TRUNCATE TABLE t3;
SET @@SESSION.foreign_key_checks = 1;
--error ER_TRUNCATE_ILLEGAL_FK
TRUNCATE TABLE t1;
TRUNCATE TABLE t2;
TRUNCATE TABLE t3;
LOCK TABLES t1 WRITE;
SET @@SESSION.foreign_key_checks = 0;
TRUNCATE TABLE t1;
SET @@SESSION.foreign_key_checks = 1;
--error ER_TRUNCATE_ILLEGAL_FK
TRUNCATE TABLE t1;
UNLOCK TABLES;
DROP TABLE t3,t2,t1;
SET @@SESSION.foreign_key_checks = @old_foreign_key_checks;

--echo #
--echo # Test that TRUNCATE resets auto-increment.
--echo #

CREATE TABLE t1 (a INT PRIMARY KEY NOT NULL AUTO_INCREMENT);
INSERT INTO t1 VALUES (NULL), (NULL);
SELECT AUTO_INCREMENT FROM INFORMATION_SCHEMA.TABLES WHERE table_name = 't1';
SELECT * FROM t1 ORDER BY a;
TRUNCATE TABLE t1;
SELECT AUTO_INCREMENT FROM INFORMATION_SCHEMA.TABLES WHERE table_name = 't1';
INSERT INTO t1 VALUES (NULL), (NULL);
SELECT * FROM t1 ORDER BY a;
DROP TABLE t1;